Apparatus for controlling fluid flow



y 1941. L R. A. WITTMANN 2,248,798 I APPARATUS FOR CONTROLLING FLUIDFLOW Filed Sept. 6, 1938 3 She ets-Sheet 1 30 r n z/enun Lj056r%QQ'-M,Z%726Zm My z/ y R. A. WITTMANN 2,248,798

APPARATUS FOR CONTROLLING FLUID FLOW Filed Sept. 6, 1938 3 Sheets-Sheet2 July 8, 1941. R. A. WITTMANN 2,248,798

APPARATUS FOR CONTROLLING FLUID FLOW Filed Sept. 6, 1938 3 Sheets-Sheet3 775/7) FEE/7 TU/EE T) safety devices.

Patented July 8, 1941 APPARATUS FOR CONTROLLING FLUID FLOW Robert A.Wittmann, Chicago, lll., assignor to Chicago By-Products Corporation, acorporation of Illinois Application September e, 1938, Serial No.228,494

14 Claims.

My invention relates generally to apparatus for controlling the flow offluid in a conduit and it has particular relation to valves operated inresponse to change in the magnetic characteristics of Curie pointmetals.

Curie point metals include those metals and alloys which normally areferromagnetic but which when heated sufiiciently become substantiallynon-magnetic. The temperature, or Curie point as it is called, at whichthis change in magnetic characteristics occurs on heating is a distinctproperty of each type of Curie point metal. For example, the Curie pointof nickel is 350 C. and it is at the same temperature on heating orcooling. The addition of tWo percent chromium lowers the Curie pointtemperature and causes it to take place over an interval of temperature,240 C.-280 (I, on heating. In contrast the Curie point temperature ofcobalt is at 110Q 0. Thus it is seen that Curie point metals withpractically any desired magnetic characteristics may be obtained byusing various metals and alloys.

Heat operated valves embodying my invention have certain inherentcharacteristics which admit themto wide application. They have the snapaction of solenoid operated valves'without the alternating current humwhich makes such embodiments thereof shown in the accompanying drawings,and it comprises the features of construction, combination of parts, andarrangement of elements which will be exemplified in the constructionshereinafter set forth and the scope of the application of which will beindicated in the appended claims.

For a more complete understanding of the nature and scope of myinvention, reference may be had to the following detailed description,taken in conjunction with the accompanying drawings in which:

Figure 1 is a sectional view of a valve illustrating one embodiment ofmy invention;

Figure 2' is a sectional view taken on line 2--2 of Figure 1;

Figure 3 is a sectional view of a valve illustrating yet anotherembodiment of my invention;

Figure 4 is a sectional view of another type of valve illustratinganother embodiment of my invention; and

Figure 5 is a curve of permeability versus temperature illustrating thecycle of operation of the valve-shown in Figure 4.

Referring now to Figures 1 and 2 of the drawings it will be observedthata valve shown, generally at I0, is located in a conduit II with itsinlet I2 and outlet l3 connected as shown. The

valves objectionable. In case of current failure,

valves embodying my invention will assume the safe or closed positionautomatically thus eliminating the necessity of providing them withTheheat expended to operate valves of my construction can be used forheating fluids flowing therethrough, such for instance as fuelgas.

The object of my invention, generally stated,

is to provide heat operated valves which are responsive to changes inmagnetic characteristics of Curie point metals.

Another object of my invention is to provide heat operated valves whichcan only fail in the the heat absorbability of fluids for shortening theclosing period ofvalves controlling theirflow in conduits.

Other objects of my invention will, in part, be obvious and in partappear hereinafter.

Accordingly, my invention is disclosed in the the poles of the magnet2|.

valve In comprises a valve body [4, preferably made out of anon-ferromagnetic material, with a baflle l5 separating the inlet l2from the outlet l3. In the bafile i5 is a port IS with its undersideground to form a valve seat. A chamber 20 is formed on the top of thevalve body l4 and above the port I6 for holding a permanent horseshoemagnet 2| therein. The poles of the magnet 2! rest on theshoulder 22 todefinitely-fix it in stationary relationship to the port I6. The chamber20 is closed 011' fluid tight 24 bolted .the valve port it the upperface of the disc 25 is only a few thousandths of an inch away from Ifdesired, the connection between the disc 2 and the valve member 21 canbe a spring conn tion so that, when the disc 25 touches the poles of themagnet 2|,

the spring tension will hold the valve member 21 tightly in the valveseat of the port I6. Extending from the bottom of the valve member 21 isa guide pin 28, loosely fitted in a guide sleeve 28 of a valve plug38screwed into the bottom oi the valve body I l. The plug 38 has ashoulder 3| adapted to limit the downward movement of the valve member21, thereby keeping the disc 25 in the magnetic field of the magnet 28.

An electric heater 33 is provided within thedisc 25 for heating it aboveits Curie point. The heater 33 may be made of nichrome wire and iselectrically insulated from the disc 25. The insulated leads 34 of theheater 33 are secured to the terminal screws 85 and 36 running throughthe valve body I4 and insulated therefrom. The heater 38 is energizedthrough a switch 31 from a pair of conductors 38 which may be connectedto any suitable current source, such as a 110 V. alternating currentsource. The heater 33 may be in series with a thermostat, sail switch orother equipment besides the switch 31, if desired, as will be readilyunderstood.

In describing the operation, it will be assumed that the switch 31 isopen and the heater 33 is therefore not energized. The disc 25, notbeing heated, will be below its Curie point and therefore ferromagneticand consequently it is attracted to the poles of the magnet 2|, therebyholding the valve member 21 in the closed position and closing the portI6. Under these conditions the valve I8 will be closed and no fluid cannow therethrough. Upon closing the switch 31, or otherwise completing anelectrical circuit to the heater 33, the heater 33' will heat the disc25 above its Curie point. As soon as the disc 25 is above its Curiepoint and, therefore, non-ferromagnetic, its weight, together with thatof the shaft 26 and the valve member 21, will cause it to drop allowingthe valve member 21 to drop therewith and thereby opening the port I6 sothat fluid may flow therethrough. When it is desired to stop the flow offluid through the valve I8, it is merely necessary to open the switch31, or otherwise deenergize the heater 33, thus allowing the disc 25 tocool below its Curie point and again become ferromagnetic and it will beagain attracted to the poles of the magnet 2|. Thus the valve member 21will again close the port I6 and the closing cycle of the valve I8 iscompleted.

As the attraction between the disc 25 and the magnet 2i varies inverselyas the square of the distance therebetween, when the disc 25 moves uptoward and closer to the magnet 2I its movement will become acceleratedand a snap action is thus produced. This is very desirable for it tendstoward a more perfect closing of the valve I8. It is apparent that, whenfluid is flowing through the valve I8, it will be in heat conductiverelation with the disc 25. And, since the form a valve seat. A chamber11 is formed on the top of the valve body 14 and above the port 16 forholding a permanent magnet 18. The chamber 11 is closed by a. cap 18 ofa non-ferromagnetic material. A shaft 88 extends from the magnet 18 forsupporting at its lower end a valve member 8| adapted to seat in thevalve seat of the port 16. The shaft 88 is of such a length that, whenthe ends of the poles of the magnet 18 are a few thousandths of an inchaway or almost touching the cap 18, the valve member BI is tightlyseated and closing the port 16. A shoulder 82 holds the magnet .18 inproper operative position. In order that the magnet 18 can be attractedto the cap 18 an electric heater element 85, itself composed of Curiepoint metal, is provided on the top of the cap 18. The heater 85 isconnected through a switch 88 to a pair of suitably energized conductors81. When the switch 86 is closed and current is flowing through theheater 85, it is heated above its Curie point and becomes non-magnetic.

In operation, when the switch 86 is opened, the heater 85 of Curie pointmetal will be ferromagnetic and the magnet 18 will be attracted thereto,thereby holding the valve member 8i tightly seated in the valve seat ofthe port 16.

I The valve 18 is then in the closed position. Upon fluid will usually,it not always, be below the 12 and outlet 13 connected as shown. Thevalve 18 comprisesa valve body 14, preferably made of anon-ferromagnetic material, with a baflle 15 separating the inlet 12from the outlet 13. In the baille 15 is a port 16 with its undersideground to closing the switch 86, the heater is almost instantly heatedabove its Curie point and becomes non-magnetic. When the heater 85becomes non-magnetic, the magnet 18 will drop onto the shoulder 82 andthe port 16 will be opened. Now when the switch 86 is opened, the heater85 will cool and the magnet 18 will be attracted thereto and again thevalve 18 will be closed. Since, in this embodiment of the invention theheating element 85 itself is the body of Curie point metal, the time forheating it above ,its Curie point is relatively short and consequentlythe operation of the valve 18 is correspondingly'fast. It will beunderstood that the switch 86 may be replaced by or operated inconjunction with a thermostat, liquid level control, sail switch or anyother desired device.

With a view to providing a valve, embodying my invention, that isparticularly useful in controlling gas fiow in cold weather or under lowtemperature conditions, I provide a valve shown, generally, at 88, inFigure 4 of the drawings. The valve 88 is provided for controlling gasflow in a gas line 8I with its inlet 82 and outlet 93 connected asshown. The valve 88 comprises a valve body 84, made perferably ofnonferromagnetic material, which is divided into an upper chamber 85 anda lower chamber 86 by the ballle 81. 'I'ne'chambers 85 and 86 are closedby plates 88 and 88 respectively, which are held in place by screws, asshown. A port I88 joins the upper chamber 85 and lower chamber 86 and isformed by a collar I8I of Curie point metal extending through the-baflle81. The port I88 can be closed by a disc I82 of non-ferromagneticmaterial which his against the bottom of the collar MI. The disc I82 iscarried on the poles of a horseshoe magnet I83 which is disposed in thelower chamber 86. When the magnet I83 is not attracted to the collarI8I, it rests on the plate 88 and within operative distance of thecollar I8I. An electric heater I84 surrounds the top of the collar mland its terminal leads are connected to the screw terminals I85 and I86which pass through the valve body 85 and are insulated therefrom. Theterminals I85 and I86 are in turn connected through a switch IN to apair of suitably energized conductors I08. When the switch I] is closedand current is passing through the heater I04, the collar I0! will beheated above its Curie point and will therefore be non-magnetic.

In operation, when the switch I0! is opened, the heater I04 will bedeenergized and the collar IOI will be cooled and therefore becomeferromagnetic. The magnet I03 will be attracted thereto and the portI00.will be closed by the disc I02 fitting over the bottomof the collarIOI. Accordingly, the valve 90 will be closed and gas flow in the line9| shut off. Now if the switch III] is closed} the heater I04 will beenergized, thereby heating the collar IOI above its Curie point andcausing it to become non-magnetic. When the collar IIII becomesnon-magnetic, the magnet I03 will no longer be attracted thereto, andwill fall, drawing the disc I02 away from the collar IOI thereby openingthe port I00 and allowing gas to flow through the valve 90. In order toclose the valve 90, it is only necessary to open the switch I01thereby'deenergizing the heater I04 and allowing the collar IOI to coolbelow its Curie point and become ferromagnetic. The magnet I03 will thenbe attracted thereto and the port I00 will be closed by the disc I02.

When valves for gas lines become cold, such as in cold weather, oftenhigher boiling point constituents of these gases condense on the valveseats and other operating parts and thereby give rise to faultyoperation, such as sticking shut or failure to close tightly. Thus withgas, such as illuminating and other similar gases, tar deposits arefrequently formed. Since, in the valve 90, when gas is flowingtherethrough, the collar IN is continually heated by the heater I04, theformation of tarry and like deposits on it is prevented. Consequently,the valve 90 will not stick because the collar IOI is heated and thusdeposits are never present. Another advantage of this valve is that thecollar IOI of Curie point metal is directly exposed to the gas flowingthrough it and hence, when the heater I04 is deenergized, it'is rapidlycooled by this flow of gas and the time for closing is shortenedaccordingly. It is also apparent that the gas flowing through the valve90 receives heat from the collar IOI and therefore the electric energysupplied to the heater I04 for operation of the valve 90 is not entirelywasted.

The cycle of operation of the valve 90 is made more clear by a referenceto the curve shown in Figure 5. Although the curve will be discussedwith particular reference to the cycle of operation of valve 90 inFigure 4, it is generally characteristic of the cycles of operation ofthe other valves previously described. The permeabilities P of thecollar, IOI of Curie point metal are represented as ordinates of thecurve and the temperatures T are represented as abscissae. When theswitch I0I is opened the permeability and temperature of the collar IOIare as designated at A. When the switch I01 is closed, and,

allowing gas to flow. The flow of gas will cool the collar IOI beingsupplied with heat from the heater I04 and the normal operatingpermeability and temperature will be as indicated at C. However, thepermeability at C will not be sufficient to allow the magnet I03 torise. Now when the heater I04 is deenergized, the collar IOI will cooland being aided by the cooling effect of the continued gas flow, itspermeability will rise sharply as indicated at D and will be suflicientto allow the magnet I03 to be attracted thereto and thereby close thevalve 90. After closing, the collar will slowly 0001 back to thetemperature indicated at A. It will be understood that some of thevariables affecting the shape of this curve are; size of the heater,particular Curie point metal involved, quantity of gas flowing,temperature of gas flowing, and the ambient temperature in which thevalve operates. Accordingly, a wide variety of operating cycles arepossible.

It will be seen that on either opening or closing of the valves, snapaction is obtained. This is apparent since, when the magnets or membersof Curie point metal are released, they drop rapidly and when attractedthey accelerate as the distance between them decreases, as hereinbeforedescribed.

Although in all of the foregoing embodiments of my invention the valvesare normally closed when the bodies of Curie point metal are not heatedabove their Curie points and are open when they are heated above theirCurie points, it will be understood that by placing the valve closingmembers above the valve ports, instead of below them, the valves will benormally closed when the bodies of Curie point metal are heated abovetheir Curie points and will be open when the bodies of Curie point metalare not heated above their Curie points.

In all of the instances in which permanent magnets are shown ordescribed, it will be understood that they can be replaced byelectromagnets if these are desired for any reason.

Since certain further changes'can be made in the foregoingconstructions, and different embodiments of the invention may be madewithout departing from the scope thereof, it is intended that all mattershown in the accompanying drawings or described hereinbefore shall beinterpreted as illustrative, and not in a limiting sense.

- I claim as my invention:

1. Means for controlling the flow of fluid in a conduit comprising, incombination, valve means in the conduit including a valve member movablebetween open and closed positions, magnet means operatively connected toand movable with said valve member, a body of Curie point metalstationarily mounted in the field of said magnet means, said valvemember being in the closed position when said body of Curie point metalis below its .Curie point and in the open position when said body ofCurie point metal is above its Curie point, and means for heating saidstationarily mounted body of Curie point metal above its Curie point toeffect movement of said valve member to the open position.

2. Means for controlling the flow of fluid in a conduit comprising, incombination, valve means in the conduit including a valve member movablebetween open and closed positions, relatively movable cooperatingmagnetic members one being a permanent magnet and the other being a bodyof Curie point metal, said valve member being operatively connected toand movable with one of said magnetic members, and circuit means forconnecting an electrical current source across said body of Curie pointmetal for heating the same above its Curie pointby current flowtherethrough to change its magnetic characteristics and thereby effectcontrol of movement of said valve member.

3. Means for controlling the flow of fluid in a conduit comprising, incombination, valve means in the conduit including a valve member movablebetween open and closed positions, relatively movable cooperatingmagnetic members one being a permanent magnet and the other being a bodyof Curie point metal, said valve member being operatively connected toand movable with one of said magnetic members and being in the closedposition when said bodyof Curie point metal is below its Curie point andin the open position when said body of Curie point metal is above itsCurie point, and circuit means for connecting an electrical currentsource across said body of Curie point metal for heating the same aboveits Curie point by current flow therethrough to change its magneticproperties and thereby effect movement of said valve member to the openposition.

5. Means for controlling the flow of fluid in a conduit comprising, incombination, valve means in the conduit including a valve member movablebetween open and closed positions, magnet means operatively connected toand movable with said valve member, an electric heater elementstationarily mounted in the held of said magnet means and formed ofCurie point metal, and circuit means for connecting an electricalcurrent source across said electric heater element for heating the sameabove its Curie point by current flow therethrough to change itsmagnetic properties and thereby efiect movement of said valve member tothe open position.

5. Means for controlling the flow of fluid in a conduit comprising, incombination, valve means in the conduit including a valve member movablebetween open and closed positions and a valve seat for receiving saidvalve member formed in part, at least, of Curie point metal, magnetmeans operatively connected to and movable with said valve member, saidvalve member being in the closed position when said Curie point metal isbelow its Curie point and in the open position when said Curie pointmetal is above its Curie point, andmeans for heating said valve seat toheat said Curie point metal above its Curie point to effect movement ofsaid valve member to the open position.

6. Means for controlling the flow of fluid in a conduit comprising incombination, valve means in the conduit including a valve member movablebetween open and closed positions and a valve seat for receiving saidvalve member formed in part, at least, of Curie point metal, magnetmeans operatively connected toand movable with said valve member, saidvalve member being in the closed position when said Curie point metal isbelow its Curie point and in the open position when said Curie pointmetal is above its Curie point, and means for heating said valve seat toheat said Curie point metal above its Curie point to effect movement ofsaid valve member to the open positiomthe heat applied to said valveseat for eflecting movement of said valve member to the open positionbeing sufllcient to prevent'condensation ot the fluid thereon.

'7. Means for controlling the flow of fluid in a conduit comprising, incombination, valve means in the conduit including a valve member movablebetween open and closed positions and a valve seat for receiving saidvalve member formed in part, at least, of Curie point metal, magnetmeans operatively connected to and movable with said valve member, saidvalve member being in the closed position when said Curie point metal isbelow its Curie point and in the open position when said Curie pointmetal is above its Curie point, and means for heating said valve seat toheat said Curie point metal above its Curie point to effect movement ofsaid valve member to the open position, the Curie point metal of saidvalve seat being in substantial heat conducting relation with the fluidflowing through said conduit whereby, when heat is no longer appliedthereto, it is rapidly cooled by conduction of heat therefrom to thefluid and said valve member is quickly moved to the closed position.

8. Means for controlling the flow of fluid in a conduit comprising, incombination, valve means in the conduit including a valve member movablebetween open and closed positions and a valve seat for receiving saidvalve member formed in part, at least, of Curie point metal, a permanentmagnet operatively connected to and movable with said valve member, saidvalve memher being in the closed position when said Curie point metal isbelow its Curie point and in the open position when said Curie pointmetal is above its Curie point, electrical heater means operativelyassociated with said valve seat, and circuit means for connecting saidelectrical heater means to a current source for energizing the same andthereby heating said Curie point metal above its Curie point to effectmovement of said valve member to the open position, the heat applied tosaid valve seat for eiiecting movement of said valve member to the openposition being sufficient to prevent condensation of the fluid thereon,and the Curie point metal to said valve seat being in substantial heatconducting relation with the fluid flowing'through said conduit whereby,when heat is no longer applied thereto, it is rapidly cooled byconduction of heat therefrom to the fluid and said valve member isquickly moved to the closed position.

9. Means for controlling the flow of fluid in a conduit comprising, incombination, valve means in the conduit including a valve member movablebetween open and closed positions, magwhen it is above the Curie point,and means for flow, a valve member cooperating with said port forcontrolling the flow of fluid through the same, relatively movablecooperating magnetic members one being arranged to produce magnetic fluxand the other being a body of Curie point metal, said valve member bbingoperatively connected to and movable with one of said magnetic membersand the assembly being wholly contained within said casing and biased toa predetermined position with respect to said port, and means forchanging the temperature of said Curie point metal to effect movement ofsaid valve member to the open and closed positions and vice versa inaccordancewith the temperature of said Curie point metal with respect toits Curie point.

11. Means for controlling the flow of fluid in a conduit comprising, incombination, a fluid tight casing interposed in said conduit and havinga valve port through which the fluid can flow, a valve membercooperating with said port for controlling the flow of fluid through thesame, relatively movable cooperating magnetic members one being arrangedto produce magnetic flux and the other being a body-of Curie pointmetal, said valve member being operatively connected to and movable withone of said magnetic members and the assembly being wholly containedwithin said casing and biased to a predetermined position with respectto said port, and means for electrically heating said Curie point metalto efiect movement of said valve member from one position to anotherwhereby said port is capable of being opened and closed in accordancewith the temperature of said Curie point metal with respect to its Curiepoint.

12. Means for controlling the flow of fluid in a conduit comprising, incombination, a fluid tight casing interposed in said conduit and havinga valve port" through which the fluid can flow,

a valve member cooperating with said port for controlling the flow offluid through the same, relatively movable cooperating magnetic membersone being arranged to produce magnetic flux and the other being a bodyof Curie point metal, said valve member being operatively connected toand movable with one of said magnetic members and the assembly beingbiased to a predetermined position with respect to said port, and meansfor electrically heating said Curie point metal to effect movement ofsaid valve member from one position to another whereby said port iscapable of being opened and closed in accorda conduit comprising, incombination, a fluid tight casing interposed in said conduit and havinga valve port through which the fluid can flow, a valve membercooperating with said port for controlling the flow of fluid through thesame,

relatively movable cooperating magnetic members within said casing onebeing arranged to produce magnetic flux and the other being a body ofCurie point metal, said valve member being operatively connected to andmovable with one of said magnetic members and the assembly being biasedto a predetermined position with respect to said port, an electricheater within said casing for heating said Curie point metal, andconductor means extending from said heater through said casing forconnection to a current source.

14. Means for controlling the flow of fluid in a conduit comprising, incombination, a fluid tight casing interposed in said conduit and havinga valve port through which the fluid can flow, a valve membercooperating with said port for controlling the flow of fluid through thesame, relatively movable cooperating magnetic members within said casingone being arranged to produce magnetic flux and the other being a bodyof Curie point metal, said valve member being operatively connected toand movable with said body of Curie point metal and the assembly beingbiased to a predetermined position with respect to said port, anelectric heater canied by said body of Curie point metal for heating thesame, and conductor means extending from said heater through said casingfor connection to a current source.

ROBERT A. WI'I'IMANN.

